Gas lighter burner ignition device

ABSTRACT

A lighter ignition mechanism includes a rectangular magnetic yoke, one leg of which is a permanent magnet, another leg of which is swingable to a yoke opening position, and a coil being wound upon another leg. A burner includes a metal top plate having a central nozzle opening communicating with a gaseous fuel source and defining a plate electrode and a needle electrode is resiliently biased to contact the plate electrode at a point offset from the nozzle, the electrodes being connected to the winding with the needle electrode positive. A resilient arm is connected to the swingable leg to, upon depression, open a gas valve to the nozzle, open the yoke, and then separate the electrodes.

United States Patent 1191 Makino 1 July 16, 1974 1 1 GAS LIGHTER BURNERIGNITION DEVICE [75] Inventor: Minoru Makino, Tokyo, Japan [73] Assignee: Kabushiki Kaisha Tanita Seisakusho, Tokyo-to, Japan 22 Filed:Nov. 15, 1973 211 Appl. No.: 416,155

Related US. Application Data 1 Division of Ser. No. 259.7 10.1une5.1972.

Oyamada et a1 317/81 X 3,424,950 1/1969 Halm 317/93 3,442,598 5/1969Halm 431/255 3,444,435 5/1969 Halm i 1 317/81 3,449,636 6/1969 Wosylus i317/81 3,559,131 1/1971 shindler 335/229 10/1972 Halm 317/81 PrimaryExaminerVolodymyr Y. Mayewsky 5 7 ABSTRACT A lighter ignition mechanismincludes a rectangular magnetic yoke, one leg of which is a permanentmagnet, another leg of which is swingable to a yoke opening position,and a coil being wound upon another leg. A burner includes a metal topplate having a central nozzle opening communicating with a gaseous fuelsource and defining a plate electrode and a needle electrode isresiliently biased to contact the plate electrode at a point offset fromthe nozzle, the electrodes being connected to the winding with theneedle electrode positive. A resilient arm is connected to the swingableleg to, upon depression, open a gas valve to the nozzle, open the yoke,and then separate the electrodes.

6 Claims, 13 Drawing Figures 1 GAS LIGHTER BURNER IGNITION DEVICEREFERENCE TO RELATED APPLICATION The present application is acontinuation-in-part of a division of co-pending US. Pat. applicationSer. No. 259,710, filed June 5, 1972.

BACKGROUND OF THE INVENTION The present invention relates generally toimprovements in electrical ignition devices, and it relates particularlyto an improved electromagnetic mechanism for producing an electricaldischarge in the proximity of a lighter fuel outlet or burner nozzle.

Many forms of electromagnetic lighter ignition mechanisms have beenproposed and these generally include a step up transformer whosesecondary winding is connected to spaced discharge electrodes in thevicinity of the lighter nozzle. The transformer includes a primarywinding which is rapidly energized or deenergized by an associatedbattery and switch arrangement or a transformer magnetic yoke includes apermanent magnetand a movable leg in the yoke magnetic path so that adischarge is produced between the electrodes attendent to the separationof the movable yoke leg whereby to ignite the fuel, which may be, forexample, in gaseous form.

The conventional and proposed ignition mechanisms of the above typepossess numerous drawbacks and disadvantages, being generallycharacterized by an electrical discharge of. such short duration as tonecessitate a very close time correlation between the opening of thelighter fuel nozzle and the establishment of the electrical dischargeand hence very close manufacturingtolerances and frequently complicatedmechanisms and very low reliability. Furthermore, in the type ofelectromagnetic ignition mechanism heretofore proposed, the high voltagestep up transformer required a primary as well as secondary winding,which is of considerable bulk, so it has been impractical to produce alighter employing this type of ignition system which is compact enoughfor use as a conventional pocket lighter, but is limited to use as astationary type of lighter and otherwise leaves much to be desired.

SUMMARY OF THE INVENTION It is a principal object of the presentinvention to provide an improved ignition mechanism.

Another object of the present invention is to provide an improvedelectromagnetic ignition mechanism in which the need for batteries isobviated and which is so compact as to be suitable for portable pocketlighters.

A further object of the present invention is to provide an ingnitionmechanism of the above nature characterized by its simplicity,ruggedness, high reliability, obviation of close operational tolerences,low cost and high versatility.

The above and other object of the present invention will become apparentfrom a reading of the following description taken in conjunction withthe accompanying drawings which illustrate preferred embodimentsthereof.

In a sense the present invention contemplates the provision of anignition device comprising a solenoid, a pair of discharge electrodesincluding a plate electrode and a needle electrode movable betweennormally closed contacting and open separated positions and coupled toopposite "terminals of the solenoid, means for producing a currentinducing pulse of varying magnetic flux through the space delineated bythe soleniod, and means foropening the electrodes following theinitiation of said magnetic pulse and during the presence of inducedcurrent.

In its preferred form the needle electrode is positioned proximate thefree end of a resilient arm which normally urges the electrodes intoengagement. The solenoid is wound about a leg ofa magnet yoke whichincludes, as sections thereof forming a normally closed magnetic path, apermanent magnet and a leg movable between a yoke closing'and openingpositions and normally being in a closed position completing themagnetic path. A resilient lever is provided for swinging the movableleg to its open positon and the movable yoke leg is advanced during itsopening to engage the needle electrode carrying arm and separate theelectrodes following the opening of the yoke and while the magneticallyinduced current is present in the solenoid.

The electrical discharge by reason of the separation of the electrodesfollowing the start of and during the presence of the induced current isof such a nature that it is hot and of relatively long duration so as toreliably insure the ignition of the fuel and the mechanism is simple,rugged, compact and inexpensive.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1(a) is a top plan view of thedischarge electrodes of an ignition mechanism embodying the presentinvention;

FIG. 1(b) is a fragmentary schematic front elevational view of theimproved mechanism;

FIG. 1(c) is a schematic view of the improved mechamsm;

FIG. 2(a) and 2(b) are diagrams showing the characteristic curve of thedischarge voltage as related to the air gap formed between the dischargeelectrodes;

FIGS. 3(a) to 3(d) are diagrams showing the variation in magnetic fluxpassing through the ignition coil upon the opening of the magnetic yoke,the time of separation of the discharge electrodes and the variation ofeletric current'and output voltage respectively in the coil as relatedto time;

FIG. 4 is a front elevational view of another embodiment of the presentinvention;

FIG. 5 is a view similar to FIG. 4 with the mechanism shown in activatedcondition; and

FIG. 6 is a fragmentary left hand view of the burner and electrodemechanism shown in FIGS. 4 and 5; and

FIG. 7 is a sectional view taken along line 7-7 in FIG. 6.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 2 is a magnetic leg la aboutwhich'is wound a suitable insulated coil or solenoid 4. Completing theyoke 1 is an iron piece or magnetic leg 3 whichextends between the topfaces of andbridges legs la and 2, being hinged to the top outer cornerof leg 2 so as to be swingable out of engagement with the top face ofleg from its closed position to a position opening the yoke 1 andthereby sharply reducing the magnetic field through solenoid 4 by way ofleg 1a to produce a sharply dropping magnetic flux pulse through thesolenoid. To facilitate the rapid opening of leg 3 a lever or handle 3bis secured to the outer face of and separated from leg 3 by a spacer 2aso that inward pressure on handle 3b effects the snap opening-of leg 3.

It is important to note that the coil 4 is wound around the yoke leg 1awitha minimum of distributed capacity in order to facilitate thedevelopment of an arc and to suppress any spark quenching action.The-output terminals of coil 4 are connected with suitable shielding toa pair of discharge electrodes 6 and 7, respectively, which are kept inseparable contact with each other as shown by FIG. 1(a). The electrodes6 and 7 are located above leg 3 and, as shown by FIG. 1(a), include apair of spaced parallel resilient arms, one pair of the end of which arefixed to the opposite faces of an insulator block 60. One electrode 7has a pointed tip 7a directed toward and normally'in contact with theother electrode 6, The electrodes 6 and 7 preferably comprise leafspring members provided with confronting followers and, as the movableiron piece 3 is swung out of contact with the yoke, leg la, a wedgeshaped cam member 3a projecting upwardly from iron piece 3 is ad-'vanced between the followers on electrodes 6 and 7 so that the pointedtip 7a of the electrode 7 is retracted out of contact with the electrode6. In FIGS. 1(a) and 1(b), 8 designates a burner nozzle for gaseous fuelwhich is opened as the movable iron piece 3 is brought out of contactwith the yoke leg 1a by depression of the lever 3b in any suitablemanner and is disposed slightly spaced from the electrode 6 and thepointed tip 7a of the electrode 7, as shown. It should be noted thatdischarge electrode 6 and pointed tip 7a of the discharge electrode 7are preferably returned into contact with each other as rapidly aspossible, and that the returning movement of the movable iron piece 3after the lever 31] is released is smoothly and reliably accomplished bythe'magnetic attractive force.

Considering now the operation of the ignition mechanism described above,the lever 3b is depressed to swing the movable iron piece 3 out ofcontact with the yoke leg la, about the upper end of the permanentmagnet 2 to insert and advance the team or wedge defining projection 3alocated on movable iron piece 3 between the followers on dischargeelectrodes 6 and 7 to thereby retract the pointed tip 7a of dischargeelecwith pointed tip 7a of the electrode 7 (ii). to (iv) corresponds tothe states in which both discharge electrodes 6 and 7 are spaced fromeach other with air gaps 1d,, M and Id respectively. The dischargevoltage Vd developing between the electrode 6 and the pointed tip 7a ofthe electrode 7 which varies depending upon the air gap formed betweenelectrode 6 and pointed tip 7a experiences the following sequence.First, in the state of air gap 1d,, the discharge voltage Vd consists ofan oscillating voltage of high frequency and small amplitude as shown by(ii) in FIG. 1(b), which effects a socalled shower discharge; when thestate of air gap [d 7 is attained, there is developed a dischargevoltage the yoke leg 1a. FIG. 2(b) shows a characteristic curve whichuniformly rises and an arc occurs as the air gap across the electrode 6and the pointed tip 7a' of the electrode 7 increases; and finally thedischarge voltage Vd reaches the maximum level (approximately 2,500volts although it may be more-or less, for example, as low as 1,000volts) when the state of air gap Id is attained (i.e., when the lever 3bis depressed substantially to the final stage of depression) andthereafter a state of resonance occurs which is a function of theinductance and distributed capacity, substantially corresponding to selfinductance and distributed capacity of the coil 4, in which state adampedoscillation voltage occurs.

r The time'point at which the maximum voltage level is developed iswithin the range between 800M and 1,200M seconds after the separation ofthe electrode 6 and the pointed tip 7a and the first peak of the dampedvoltage appears approximately 200M seconds after the time of the maximumvoltage level. The nozzle 8 for gaseous fuel, therefore may be openedapproximately from the moment at which an air gap across the electrode 6and the pointed tip 7a occurs corresponding to the state shown by (ii)in order that the ignition of the gaseous fuel is assured by thedischarge voltage under the conditions of resonance voltage at the steps(ii) to (iv) and the following conditions as shown inFiG. 2(b).

' FIGS. 3(a) to 3(d) illustrate the variation in magnetic flux passingthrough coil 4 from the moment at which the opening of movable ironpiece 3 is initiated, the

time point at which the electrode 6 and the pointed electrode tip 7a areseparated from each other, and the variation of electric current andoutput voltage respectively in coil 4 as related to time t. As is seenfrom FIG. 3(b), the variation of electric, current and output voltagereaches a maximum at the moment at which the electrode 6 and the pointedtip 7a are separated from each other. I

The pointed tip 7a of the electrode7 and the portion of the electrode 6that is engageable by pointed tip 7a, including the area adjacent to tip7a, are susceptible to soot and the other dust which progressivelyaccumulates thereon with repeated ignitions. This soot and dust are,however, removed under cleaning effect not only of the chatteringphenomenon occurring during the separation of both electrodes 6 and 7which serves to clean these contact surfaces, but also by reason of ametal catalytic action during conbustion of the gaseous fuel, so thateffective and reliable ignition is always assured.

Referring now to FIGS. 4 to 7 of the drawings which illustrate anotherembodiment of the present invention, the reference numeral 10 generallydesignates a liquified gas lighter employing the improved ignitionsystem, the lighter including at its base a pressurized liquified fuelgas tank 11 of known construction. The tank 11 is provided at its topwall with a conventional tubular valve member which is biased to adepressed closed condition, the raising of valve member 12 providingcommunication through the valve to the tank 1 1, a valve openingadjustment member of known type (not shown) being provided andaccessible at the tank bottom wall which also contains a gas fillerwall. The tank 11 is normally filled with liquified butane.

A vertical U-shaped mounting bracket, preferably formed of a rigidinsulating material such as a thermoset polymeric resin, is mounted atopthe tank 11 and includes a horizontal side leg 13 provided with a bottomflange 14 overlying and secured to the top wall of tank 11. A cross armprojects upwardly from one end of side arm 13 and terminates at its topin a horizontal side arm 16 substantially co-extensive and coplanar withside arm 13. A rectangular frame magnetic yoke 17 for affording a lowreluctance magnetic path for the magnetic field effected by a suitablehigh strength permanent magnet 18 which constitutes a leg of the yokeand extends upwardly along the cross arm of the mounting bracket fromone end a horizontal laminated yoke bottom leg 19 which rests on flangel4 and is secured to side arm 13 along which it extends. Alsoprojectingupwardly from the yoke bottom leg 19 and transversely spaced from thepermanent magnet leg 18 is a verticallaminated magnetic leg 20 which isengaged by a coaxial solenoid or winding 21 wound in a suitableinsulated spool including end flanges 22.

Secured to and extending along the front face of permanent magnet yokeleg 18 is a vertical plate 23 having an upper end projecting above yokeleg 18 and having an arcuate concave bearing recess 24 formed therein.Completing the yoke 17 is a swingable laminated magnetic yoke leg 26having opposite slightly raised portions 27 at opposite ends of itsunderface which, in the closed condition of yoke 17 engage the top endfaces of yoke legs 18 and 20. Secured to the end of the front face ofyoke leg 26 is a shaft defining circular head 28 which is borne by theedge of arcuate recess 24, so that the opposite end of yoke leg 26 isswingableinto and out of contacting engagement with the confronting endface of yoke, leg 20. A resilient or spring arm 29 is secured at its topend to the end face of yoke leg 26 proximate yoke leg 18 and dependsfrom yoke leg 26 and downwardly, outwardly, diverges from the outer sideface of yoke leg 26 proximate yoke leg 18 yoke leg 18 when yoke leg 26is in its closed condition as shown in FIG. 1(a). The arm 29 terminatesatis bottom at about the medial level of bracket flange l4.

Projecting forwardly from the lower border of the free end of bracketarm 16 is an integrally formed bracket arm 30 having an enlarged opening32 therein and having superimposed thereon a metal annulus 33 providedwith a tab 34 which is connected to one terminal lead 36 of the winding21. A cap shaped metal burner member 37 is coaxially positioned onannulus 33 and includes a circular top wall 38 which defines a plateelectrode having a nozzle defining central opening. A skirt wall 40depends from the periphery of plate electrode 38 into engagement withannulus 33. A vertical gas outlet tube 41 is supported coaxial withnozzle opening 39 with its top outlet below the level of plate electrode38 so that gas flowing from the tube 41 is admixed with air as it flowsto the nozzle 39, the chamber delineated by the burner 37 communicatingwith the atmosphere. The tube 41 is connected by a flexible tube 42 tothe outlet valve 12. A vertically extending open topped shield 43engages the burner 47 and has a longitudinal peripheral opening facingthe opposite side of the lighter 10.

An integrally formed insulator arm 44 projects forwardly from the upperright hand border of bracket arm 16. A transversely extending resilientmetal arm 46 has one end clamped between the underface of arm 46 and anunderlying metal clamp plate 47 tightened to arm 44 by a pair of screws48, one of the screws 48 having an annular electrical connectorunderlying and clamped by its head, the connector being connected to theother terminal lead 49 of the winding 21. The free end of arm 46terminates in a upwardly directed leg 50 joining a longitudinallyprojecting arm 51 which terminates in a vertically depending pointedelectrode defining leg 52. The side edges of arm 51 converge toward theouter end thereof and the side edges of leg 52 converge downwardly to asharp tip which is bevelled to form a needle tipped electrode. Suitablyaffixed to the underface of arm 46 immediately inwardly of leg 50 and invertical alignment with the free end of yoke leg 26 is a downwardlyconvex rubber bumper 53.

A valve actuator member 54 extends along and slightly above flange 14and includes a bottom cross web 56 joining a vertical front wall 57 anda vertical ear 58 at one end of web 56. A pivot pin 59 secured to yokeleg 19 and bracket leg 17 engages aligned opnings in wall 57 and ear 58to swingably support the valve actuator member 54 at an end thereof. Thefree end of web 56 terminates in an outwardly, upwardly inclined lip anda slot is formed in web 56 inwardly of lip 60 and engaging a perpheralgroove in valve member 12 so that raising of the free end of actuator 54opens the valve member 12.

An elongated slide plate 63 extends along the front face of yoke leg 19and has aligned longitudinal slots 64 which respectively slideablyengage pin 59 and a transversely spaced pin 65 projecting from yoke leg19. The slide plate 63 is trensversely urged toward a right retractedposition by a tension spring 66'whose ends are engaged by the pin 65 anda screw 67 located on plate 63 to the left of pin 65. Mounted on andprojecting forwardly from slide plate 65 and slideable alongflange 14 isa wedge shaped cam member 68 having a tapered leading section 69confronting lip 60 and spaced to the right thereof when slide plate 63is in its retracted position as limited by pins 59 and 65. A leg 70depends from the right end of slide plate 63 and registers with a slotin the corresponding end face of flange 14. Projecting rearwardly fromthe bottom right corner is a rod 71 whose outer face is engaged by thebottom confronting face ,of arm 29.

The various components and elements of the lighter mechanism 10 are sodimensioned, proportioned, re-

lated and have properties that when the lighter mechanism is in itsdormant or unactuated condition, as illustrated in FIG. 1(a) the yokeleg 26 is in its closed postion engaging yoke legs 18 and 20 and belowbumper member 53, pointed electrode 52 is urged under the influence ofresilient arm 46 into firm contact with plate electrode 38 and cam 68 isdisposed rearwardly of lip 60 under the influence of spring 66 so thatvalve 12 is maintained closed. The resilience of arm 29 is such thatupon the initial flexing thereof inwardly before sufficient force isapplied to swing yoke leg 26 to its open position as shown in FIG. l(b), it urges slide plate 63 and cam 68 to the left to engage lip 60 andraise the cam actuator 54 to open valve 12. Upon further flexing of arm29 the torque thereon is sufficient to swing yoke arm 26 about pin 28out of engagement with yoke arm 20, the free end of yoke arm 26 strikingthe bumper 53 to raise arm 46 and separate electrodes 38 and 52. Theopening of the magnetic yoke establishes a high voltage and currentbetween the electrodes 38 and 52, causing arcing which ignites the gasflowing through nozzle 39 by way of the open valve 12.

The resilient arm 46 advantageously urges the tip of needle electrode 52into engagement with plate electrode'38 at a pressure of between 40 and200 grams and the side edges of electrode 52 converge at an angle ofbetween 1 and 90. It is important that the point of contact betweenelectrodes 38 and 52 be offset from nozzle 39 and the distance betweenthe point of contact between electrodes 38 and 52 and the centre line ofnozzle 39 be between 0.5 and 3.0 millimeter. In addition, the windingterminals are connected to electrodes 38 and 52 so that upon opening ofyoke leg 26 to produce a magnetic flux pulse through winding 21, thepositive side of the resulting electrical pulse is applied to needleelectrode 52. The solenoid 21 advantageously has between 1,000 and20,000 turns of wire having diameters between 0.1 and 0.025 millimeters.

While there have been described and illustrated preferred embodiments ofthe present invention, it is apparent that numerous alterations,omissions and additions may be made without departing from the spiritthereof.

I claim:

l. A gas burner device comprising a soleniod, a magnetic yoketransferable between an open and closed condition, and including a firstleg registering with said soleniod, a permenent magnet second leg and athird yoke leg pivotally supported for swinging between a yoke closingand a yoke opening position, a plate electrode connected to one terminalof said soleniod, a nee-- dle electrode connected to the oppositeterminal of said soleniod and separably, resiliently urged intoengagement with said plate electrode, means for directing a flow ofgaseous fuel proximate said plate electrode, means for opening saidelectrodes in operative association with the opening of said yoke and aresilient actuating arm extending from the pivoted end of said thirdyoke leg and being at an angle thereto.

2. The device of claim 1, wherein said plate electrode has a nozzledefining aperture formed therein, said flow directing means directingsaid gaseous flow through said aperture.

3. The device of claim 2, wherein the point of en-. gagement betweensaid electrodes is offset from the center of said aperture between 0.5and 3.0 millime ters.

4. The device of claim 3, including a resilient arm, means supportingone end of said arm above said yoke third leg, said needle electrodebeing located proximate the free end of said resilient arm and urgedthereby into engagement with said plate electrode, and said third 6. Thedevice of claim 3, wherein said solenoid and I permanent magnet yoke areso oriented that the positrode.

1. A gas burner device comprising a soleniod, a magnetic yoketransferable between an open and closed condition, and including a firstleg registering with said soleniod, a permenent magnet second leg and athird yoke leg pivotally supported for swinging between a yoke closingand a yoke opening position, a plate electrode connected to one terminalof said soleniod, a needle electrode connected to the opposite terminalof said soleniod and separably, resiliently urged into engagement withsaid plate electrode, means for directing a flow of gaseous fuelproximate said plate electrode, means for opening said electrodes inoperative association with the opening of said yoke and a resilientactuating arm extending from the pivoted end of said third yoke leg andbeing at an angle thereto.
 2. The device of claim 1, wherein said plateelectrode has a nozzle defining aperture formed therein, said flowdirecting means directing said gaseous flow through said aperture. 3.The device of claim 2, wherein the point of engagement between saidelectrodes is offset from the center of said aperture between 0.5 and3.0 millimeters.
 4. The device of claim 3, including a resilient arm,means supporting one end of said arm above said yoke third leg, saidneedle electrode being located proximate the free end of said resilientarm and urged thereby into engagement with said plate electrode, andsaid third yoke leg upon swinging to its yoke open position engages saidresilient arm to swing it in an electrode separating direction.
 5. Thedevice of claim 4, wherein said gas flow directing means conprises anormally closed valve providing communication with a source of said gasand including a valve opening member located in the path of the free endof said actuating arm.
 6. The device of claim 3, wherein said solenoidand permanent magnet yoke are so oriented that the positive side of thepulse output from said solenoid upon opening of said yoke is connectedto said needle electrode.